In addition to the previous article in this post you can find more encryption information. The following post explains the ideas behind most of the popular encryption methods. It also gives a brief history of encryption, and you can read about the RSA encryption explanation.

C includes operators to manipulate memory at the bit level. This is useful for writing low level hardware or operating system code where the ordinary abstractions of numbers, characters, pointers, etc… are insufficient - an increasingly rare need. Bit manipulation code tends to be less “portable”.